Vulnerability record

CVE-2026-81963

Microsoft Windows Link Following Vulnerability

HighExploitation confirmedCISA KEV

What should I do?

This vulnerability is in the CISA Known Exploited Vulnerabilities catalog: attackers are using it. If you run Windows, fix it now.

CISA required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

US federal civilian agencies must remediate by Sep 22, 2026.

Patch status

Official fix available since Sep 29, 2026

Apply the vendor's update to every affected system. Check the fixed-in versions below where known.

Basis: NVD patch reference

Patch or advisory on msrc.microsoft.com (opens in a new tab)

Description

Improper link resolution before file access ('link following') in Windows Update Stack allows an authorized attacker to elevate privileges locally.

Source: NIST National Vulnerability Database. Official vulnerability data, reproduced as published.

Affected products

Products affected by this vulnerability, with versions and the source of each entry
Product	Vendor	Source
Windows	Microsoft	KEV

Sources: KEV = CISA Known Exploited Vulnerabilities catalog. Version details have not been published yet.

Intelligence timeline

Developments from the last 30 days, newest first.

CVSS scoredUpdateKEVSep 29, 2026
CVE-2026-81963 scored CVSS 7.8: Microsoft Windows, Microsoft Windows Link Following Vulnerability
CISA lists this as exploited in the wild. Unpatched Windows systems are exposed to active attacks now.
Basis: NIST National Vulnerability Database
Patch releasedUpdateKEVSep 29, 2026
Patch released for CVE-2026-81963: Microsoft Windows, Microsoft Windows Link Following Vulnerability
An official fix is now available for Microsoft Windows. This vulnerability is being exploited, so apply it promptly.
Basis: NVD patch reference
Added to CISA KEVSep 8, 2026
CVE-2026-81963 added to CISA KEV: Microsoft Windows, Microsoft Windows Link Following Vulnerability
CISA lists this as exploited in the wild. Unpatched Windows systems are exposed to active attacks now.
Basis: CISA Known Exploited Vulnerabilities catalog

Coverage

We have not published a story about this vulnerability yet.

References

msrc.microsoft.com https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-81963
cisa.gov https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
cisa.gov https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-ba…
nvd.nist.gov https://nvd.nist.gov/vuln/detail/CVE-2026-81963
msrc.microsoft.com https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-81963
cisa.gov https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-81963